Investigation of Microstructure and Mechanical Properties of Cast Al–10Zn–3.5Mg–2.5Cu Nanocomposite Reinforced with Graphene Nano Sheets Produced by Ultrasonic Assisted Stir Casting

Abstract

Microstructure and mechanical properties of aluminum alloy Al–10Zn–3.5Mg–2.5Cu/graphene nanoplates composites produced by ball milling and stir casting have been investigated. The presence of dispersed Graphene nano plates with high specific surface area significantly increases the strength of the composites. The microstructural studies of the alloy revealed that graphene nano plates addition reduces the grain size, but adding higher graphene nano plates content (1 wt% graphene nano plates) does not change the grain size considerably. Further investigations on tensile tests revealed that the addition of graphene nano plates increases ultimate tensile strength. Samples under T6 heat treatment (heating up to 460 °C for 8 h, quenching in water (25 °C) and aging at 120 °C for 24 h) show better strength than other samples. At higher graphene nano plates contents, the presence of graphene agglomerate on grain boundaries was found to be the favored path for crack growth. The composite containing 0.7 wt% graphene nano plates exhibits tensile strength of 582 Mpa. © 2022, American Foundry Society.